Allergic reaction - a pathological variant of interaction immune system with a foreign agent (allergen), which results in damage to body tissues.

Immune system: structure and functions

The structure of the immune system is very complex, it includes individual organs ( thymus, spleen), islands of lymphoid tissue scattered throughout the body (lymph nodes, pharyngeal lymphoid ring, intestinal nodes, etc.), blood cells (various types of lymphocytes) and antibodies (special protein molecules).

Some parts of the immune system are responsible for recognizing foreign structures (antigens), others have the ability to remember their structure, and others ensure the production of antibodies to neutralize them.

Under normal (physiological) conditions, an antigen (for example, the smallpox virus), when it first enters the body, causes a reaction from the immune system - it is recognized, its structure is analyzed and remembered by memory cells, and antibodies are produced to it and remain in the blood plasma. The next arrival of the same antigen leads to an immediate attack by pre-synthesized antibodies and its rapid neutralization - thus, the disease does not occur.

In addition to antibodies, immune reaction Cellular structures (T-lymphocytes) that are capable of secreting enzymes that destroy the antigen also take part.

Allergies: causes

An allergic reaction is not fundamentally different from the normal response of the immune system to an antigen. The difference between normality and pathology lies in the inadequacy of the relationship between the strength of the reaction and the cause that causes it.

The human body is constantly exposed to a variety of substances that enter it with food, water, inhaled air, and through the skin. IN in good condition Most of these substances are “ignored” by the immune system; there is so-called refractoriness to them.

Allergies involve abnormal sensitivity to substances or physical factors to which an immune response begins to form. What is the cause of the breakdown defense mechanism? Why does one person develop a severe allergic reaction to something that another simply does not notice?

There is no clear answer to the question about the causes of allergies. The sharp increase in the number of sensitized people in recent decades can be partly explained by the huge number of new compounds they encounter in everyday life. These are synthetic fabrics, perfumes, dyes, medicines, nutritional supplements, preservatives, etc. The combination of antigenic overload of the immune system with the innate structural features of certain tissues, as well as stress and infectious diseases, can cause a failure in the regulation of protective reactions and the development of allergies.

All of the above applies to external allergens (exoallergens). In addition to them, there are allergens of internal origin (endoallergens). Some structures of the body (for example, the lens of the eye) do not come into contact with the immune system - this is required for their normal functioning. But with certain pathological processes (injuries or infections), such natural physiological isolation is disrupted. The immune system, having discovered a previously inaccessible structure, perceives it as foreign and begins to react by forming antibodies.

Another option for the occurrence of internal allergens is a change normal structure any tissue under the influence of burns, frostbite, radiation or infection. The altered structure becomes “foreign” and causes an immune reaction.

Mechanism of allergic reaction

All types of allergic reactions are based on a single mechanism, in which several stages can be distinguished.

1. Immunological stage. When the body first encounters an antigen and produces antibodies to it, sensitization occurs. Often, by the time antibodies form, which takes some time, the antigen has time to leave the body, and no reaction occurs. It occurs with repeated and all subsequent arrivals of the antigen. Antibodies attack an antigen to destroy it and form antigen-antibody complexes.
2. Pathochemical stage. The resulting immune complexes damage special mast cells found in many tissues. These cells contain granules containing inflammatory mediators in an inactive form - histamine, bradykinin, serotonin, etc. These substances become active and are released into the general bloodstream.
3. Pathophysiological stage occurs as a consequence of the effects of inflammatory mediators on organs and tissues. Various external manifestations allergies - spasm of the bronchial muscles, increased intestinal motility, gastric secretion and mucus formation, dilation of capillaries, appearance skin rash and etc.

Classification of allergic reactions

Despite the common mechanism of occurrence, allergic reactions have clear differences in clinical manifestations. Existing classification highlights following types allergic reactions:

I type – anaphylactic , or immediate allergic reactions. This type occurs due to the interaction of antibodies of group E (IgE) and G (IgG) with the antigen and the sedimentation of the resulting complexes on the membranes of mast cells. This releases a large number of histamine, which has a pronounced physiological effect. The time for the reaction to occur is from several minutes to several hours after the antigen enters the body. This type includes anaphylactic shock, urticaria, atopic bronchial asthma, allergic rhinitis, Quincke's edema, many allergic reactions in children (for example, food allergies).

II type – cytotoxic (or cytolytic) reactions. In this case, immunoglobulins of groups M and G attack antigens that are part of the membranes own cells organism, resulting in cell destruction and death (cytolysis). The reactions proceed more slowly than the previous ones; the full development of the clinical picture occurs after a few hours. Type II reactions include hemolytic anemia and hemolytic jaundice newborns with Rh conflict (in these conditions, massive destruction of red blood cells occurs), thrombocytopenia (platelets die). This also includes complications during blood transfusion (blood transfusion), administration of medications (toxic-allergic reaction).

III type – immunocomplex reactions (Arthus phenomenon). A large number of immune complexes, consisting of antigen molecules and antibodies of groups G and M, are deposited on the inner walls of the capillaries and cause their damage. Reactions develop within hours or days after the immune system interacts with the antigen. This type of reaction includes pathological processes in allergic conjunctivitis, serum sickness (immune response to serum administration), glomerulonephritis, systemic lupus erythematosus, rheumatoid arthritis, allergic dermatitis, hemorrhagic vasculitis.

IV type – late hypersensitization , or delayed-type allergic reactions that develop a day or more after the antigen enters the body. This type of reaction occurs with the participation of T-lymphocytes (hence another name for them - cell-mediated). The attack on the antigen is provided not by antibodies, but by specific clones of T-lymphocytes that have multiplied after previous arrivals of the antigen. Lymphocytes secrete active substances - lymphokines, which can cause inflammatory reactions. Examples of diseases based on type IV reactions are contact dermatitis, bronchial asthma, and rhinitis.

V type – stimulating reactions hypersensitivity. This type of reaction is different from all previous topics that antibodies interact with cellular receptors intended for hormone molecules. Thus, antibodies “replace” the hormone with its regulatory effect. Depending on the specific receptor, the consequence of contact of antibodies and receptors during type V reactions can be stimulation or inhibition of organ function.

An example of a disease that occurs due to the stimulating effect of antibodies is diffuse toxic goiter. In this case, antibodies irritate cell receptors thyroid gland, intended for thyroid-stimulating hormone of the pituitary gland. The consequence is an increase in the production of thyroxine and triiodothyronine by the thyroid gland, the excess of which causes the picture toxic goiter(Graves' disease).

Another option for type V reactions is the production of antibodies not to the receptors, but to the hormones themselves. In this case, the normal concentration of the hormone in the blood is insufficient, since part of it is neutralized by antibodies. This is how insulin-resistant diabetes occurs (due to insulin inactivation by antibodies), some types of gastritis, anemia, and myasthenia gravis.

Types I–III combine acute allergic reactions of the immediate type, the rest are of the delayed type.

Allergies general and local

In addition to being divided into types (depending on the speed of occurrence of manifestations and pathological mechanisms), allergies are divided into general and local.

With the local version, the signs of an allergic reaction are local (limited) in nature. This type includes the Arthus phenomenon, skin allergic reactions (Overy phenomenon, Praustnitz-Kustner reaction, etc.).

Most immediate reactions are classified as general allergies.

Pseudoallergy

Sometimes conditions arise that are clinically practically indistinguishable from manifestations of allergy, but in fact they are not allergy. In pseudoallergic reactions, there is no main mechanism of allergy - the interaction of antigen with antibody.

A pseudoallergic reaction (the outdated name “idiosyncrasy”) occurs when food, drugs and other substances enter the body, which, without the participation of the immune system, cause the release of histamine and other inflammatory mediators. The consequence of the latter is manifestations very similar to a “standard” allergic reaction.

The cause of such conditions may be a decrease in the neutralizing function of the liver (with hepatitis, cirrhosis, malaria).

The treatment of any diseases of an allergic nature should be carried out by a specialist - an allergist. Attempts at self-medication are ineffective and can lead to the development of severe complications.

Types of allergic reactions

Various types of allergic reactions are familiar to almost all of us. Young children are especially susceptible to the harmful effects of allergens, so all young parents must know what symptoms characterize each type and how to properly provide first aid.

In this article, we bring to your attention a modern classification of types of allergic reactions, their symptoms and the necessary tactics for providing first aid in each specific case.

Causes of allergies

In fact, anything can cause an allergy. Each person’s body is individual, so any adult or child can develop their own intolerance to a particular product, chemical, and so on.

In most cases, the human immune system responds to the following factors:

• dust – house, street, book, as well as house dust mites;
• pollen of flowering plants;
• pet hair, saliva and secretions;
• mold or fungal spores;
• all kinds of food products. Most often, allergic reactions occur after eating citrus fruits, nuts, legumes, eggs, milk and dairy products, honey and seafood;
• bites and discharge of insects, in particular, wasps, bees, ants, bumblebees and others;
• various medications. The most powerful allergens in this category are antibiotics, in particular penicillin, and anesthetics;
• latex;
• sun and water;
• household chemicals.

Based on the type of reactions, there are 4 types of allergies, namely:

• Immediate anaphylactic reactions occur within a few minutes or 2-3 hours after the human body interacts with the allergen. At this moment, a large amount of histamine is released, which has a pronounced physiological effect. This type includes anaphylactic shock, allergic rhinitis, angioedema, atopic bronchial asthma, urticaria and almost all types of allergies in children;
• cytotoxic or cytolytic manifestations. These are reactions that proceed much more slowly than the previous type, and necessarily lead to cell death and destruction. This includes hemolytic jaundice and anemia of newborn babies as a response of the baby’s immune system to a Rh conflict with the mother, complications after the administration of certain medications, as well as any reactions caused by blood transfusion;
• immunocomplex reactions appear within 24 hours after contact with the allergen. As a result of such processes, damage to the internal walls of the capillaries occurs. Common types of allergies noted here include serum sickness, glomerulonephritis, allergic conjunctivitis, rheumatoid arthritis, systemic lupus erythematosus, hemorrhagic vasculitis and allergic dermatitis;
• Late hypersensitization can develop within a few days after the negative impact of certain factors on the human body. In most cases, it manifests itself in the form of diseases such as bronchial asthma, rhinitis and contact dermatitis.

Symptoms of different types of allergies

Contrary to popular belief, allergy symptoms do not depend on what exactly served as the allergen in a particular case, but on the organ in which the inflammatory process began to develop. Depending on the symptoms of the disease, it is possible to determine which organs are inflamed and what type of allergic reaction is currently observed.

• cough, shortness of breath and various breathing disorders indicate damage to the respiratory system. As a rule, in this case allergic bronchial asthma develops;
• sneezing, itching of the nasal mucosa, discharge from the nasal cavity, congestion indicate allergic rhinitis;
• excessive lacrimation, itching, redness and swelling of the eyelids indicate conjunctivitis due to allergies;
• An allergic reaction in the form of swelling, for example, behind the ears or in other parts of the body in most cases is angioedema. Also with this disease, swelling of the mucous membranes and skin;
• a significant decrease in blood pressure, dizziness, clouding of consciousness, respiratory arrest, fainting almost always indicate anaphylactic shock;
• finally, various allergic reactions in the form of a rash may indicate atopic or contact dermatitis, urticaria and other diseases.

The various manifestations of allergies in the form of dermatological diseases should be discussed separately.

The main types of allergic reactions that appear on the skin

Depending on the general health of the adult or child, in response to the body’s contact with certain external factors The following skin reactions may develop:

• urticaria - the skin with this disease becomes covered with a huge number of small blisters that resemble nettle burns. In some cases they grow into large plaques. Such blisters cause a lot of trouble for a sick person, since they are always accompanied by very severe itching, and if you comb them, then they will be added to it painful sensations;
• eczema. With this disease, red spots appear on the skin. rough spots, which also cause quite severe itching. After some time, the foci of inflammation open and form weeping and flaky erosions. In most cases, eczema affects the face and hands, but by and large it can appear on absolutely any part of the body, for example, behind the ears;
• With atopic dermatitis, tiny watery blisters appear. If an infection gets into the affected area, pyoderma develops. Most adults who are familiar with the manifestations of this disease suffer from its exacerbations throughout their lives. In young children, who also often experience atopic dermatitis, the immune system most often suppresses this disease as they grow older;
• neurodermatitis is characterized by the appearance of papular rashes on the skin, which tend to merge and cause a mass discomfort. Most people suffering from this disease note that they experience increased discomfort in the evening. Typically, neurodermatitis plaques appear on the neck, near the anus, as well as in the elbow and popliteal fossae. Often with this disease, allergic reactions are also noted in the form of the appearance of bumps behind the ears, which represent inflammation of the lymph nodes. However, such bumps may also indicate other ailments, so if they do not go away for a long time, consult a doctor.

First aid for allergies

First of all, to get rid of allergy symptoms, it is necessary to identify the allergen and reduce all contacts with it to a minimum. If you cannot do this yourself, consult your doctor. Modern laboratory methods research allows you to accurately determine the allergen using various tests.

• thoroughly rinse the area of ​​contact with the allergen, for example, the nasal mucosa, skin or oral cavity;
• if there is a rash, lubricate the skin with an anti-inflammatory cream, for example, “La-Cri”;
• remove the sting if the allergy is caused by an insect bite;
• Apply a cold compress to the itchy area of ​​skin;
• If you have difficulty breathing, remove all clothing;
• take an antihistamine, for example, Suprastin or Tavegil. For children, it is better to use Fenistil or Zyrtec drops;
• in severe cases, in particular with the development of angioedema, and if medications do not help, call an ambulance immediately.

You should also definitely consult a doctor if various allergy symptoms plague you regularly.

In this case, treatment should be comprehensive and carried out strictly under the supervision of a qualified doctor.

Types of allergic reactions

An allergic reaction is a pathological variant of the interaction of the immune system with a foreign agent (allergen), which results in damage to body tissues.

Immune system: structure and functions

The structure of the immune system is very complex, it includes individual organs (thymus, spleen), islands of lymphoid tissue scattered throughout the body (lymph nodes, pharyngeal lymphoid ring, intestinal nodes, etc.), blood cells (various types of lymphocytes) and antibodies (special protein molecules).

Some parts of the immune system are responsible for recognizing foreign structures (antigens), others have the ability to remember their structure, and others ensure the production of antibodies to neutralize them.

Under normal (physiological) conditions, an antigen (for example, the smallpox virus), when it first enters the body, causes a reaction from the immune system - it is recognized, its structure is analyzed and remembered by memory cells, and antibodies are produced to it and remain in the blood plasma. The next arrival of the same antigen leads to an immediate attack by pre-synthesized antibodies and its rapid neutralization - thus, the disease does not occur.

In addition to antibodies, cellular structures (T-lymphocytes) that are capable of secreting enzymes that destroy the antigen also take part in the immune reaction.

Allergies: causes

An allergic reaction is not fundamentally different from the normal response of the immune system to an antigen. The difference between normality and pathology lies in the inadequacy of the relationship between the strength of the reaction and the cause that causes it.

The human body is constantly exposed to a variety of substances that enter it with food, water, inhaled air, and through the skin. In a normal state, most of these substances are “ignored” by the immune system; there is a so-called refractoriness to them.

Allergies involve abnormal sensitivity to substances or physical factors to which an immune response begins to form. What is the reason for the breakdown of the protective mechanism? Why does one person develop a severe allergic reaction to something that another simply does not notice?

There is no clear answer to the question about the causes of allergies. The sharp increase in the number of sensitized people in recent decades can be partly explained by the huge number of new compounds they encounter in everyday life. These are synthetic fabrics, perfumes, dyes, medications, food additives, preservatives, etc. The combination of antigenic overload of the immune system with the innate structural features of some tissues, as well as stress and infectious diseases, can cause a failure in the regulation of protective reactions and the development of allergies.

All of the above applies to external allergens (exoallergens). In addition to them, there are allergens of internal origin (endoallergens). Some structures of the body (for example, the lens of the eye) do not come into contact with the immune system - this is required for their normal functioning. But with certain pathological processes (injuries or infections), such natural physiological isolation is disrupted. The immune system, having discovered a previously inaccessible structure, perceives it as foreign and begins to react by forming antibodies.

Another option for the occurrence of internal allergens is a change in the normal structure of any tissue under the influence of burns, frostbite, radiation or infection. The altered structure becomes “foreign” and causes an immune reaction.

Mechanism of allergic reaction

All types of allergic reactions are based on a single mechanism, in which several stages can be distinguished.

1. Immunological stage. When the body first encounters an antigen and produces antibodies to it, sensitization occurs. Often, by the time antibodies form, which takes some time, the antigen has time to leave the body, and no reaction occurs. It occurs with repeated and all subsequent arrivals of the antigen. Antibodies attack an antigen to destroy it and form antigen-antibody complexes.
2. Pathochemical stage. The resulting immune complexes damage special mast cells found in many tissues. These cells contain granules containing inflammatory mediators in an inactive form - histamine, bradykinin, serotonin, etc. These substances become active and are released into the general bloodstream.
3. Pathophysiological stage occurs as a consequence of the effects of inflammatory mediators on organs and tissues. Various external manifestations of allergies occur - spasm of the bronchial muscles, increased intestinal motility, gastric secretion and mucus formation, dilation of capillaries, the appearance of skin rashes, etc.

Clinical picture

What doctors say about antihistamines

Doctor of Medical Sciences, Professor Emelyanov G.V. Medical practice: more than 30 years.
Practical medical experience: more than 30 years

According to the latest WHO data, it is allergic reactions in the human body that lead to the majority of fatal diseases. And it all starts with the fact that a person has an itchy nose, sneezing, runny nose, red spots on the skin, and in some cases, suffocation.

7 million people die every year due to allergies, and the scale of the damage is such that the allergic enzyme is present in almost every person.

Unfortunately, in Russia and the CIS countries, pharmaceutical corporations sell expensive medications that only relieve symptoms, thereby hooking people on one drug or another. This is why in these countries there is such a high percentage of diseases and so many people suffer from “non-working” drugs.

Classification of allergic reactions

Despite the common mechanism of occurrence, allergic reactions have clear differences in clinical manifestations. The existing classification identifies the following types of allergic reactions:

I type – anaphylactic , or immediate allergic reactions. This type occurs due to the interaction of antibodies of group E (IgE) and G (IgG) with the antigen and the sedimentation of the resulting complexes on the membranes of mast cells. This releases a large amount of histamine, which has a pronounced physiological effect. The time for the reaction to occur is from several minutes to several hours after the antigen enters the body. This type includes anaphylactic shock, urticaria, atopic bronchial asthma, allergic rhinitis, Quincke's edema, and many allergic reactions in children (for example, food allergies).

II type – cytotoxic (or cytolytic) reactions. In this case, immunoglobulins of groups M and G attack antigens that are part of the membranes of the body’s own cells, resulting in the destruction and death of cells (cytolysis). The reactions proceed more slowly than the previous ones; the full development of the clinical picture occurs after a few hours. Type II reactions include hemolytic anemia and hemolytic jaundice of newborns with Rh conflict (in these conditions, massive destruction of red blood cells occurs), thrombocytopenia (platelets die). This also includes complications during blood transfusion (blood transfusion), administration of medications (toxic-allergic reaction).

III type – immunocomplex reactions (Arthus phenomenon). A large number of immune complexes, consisting of antigen molecules and antibodies of groups G and M, are deposited on the inner walls of the capillaries and cause their damage. Reactions develop within hours or days after the immune system interacts with the antigen. This type of reaction includes pathological processes in allergic conjunctivitis, serum sickness (immune response to serum administration), glomerulonephritis, systemic lupus erythematosus, rheumatoid arthritis, allergic dermatitis, hemorrhagic vasculitis.

IV type – late hypersensitization , or delayed-type allergic reactions that develop a day or more after the antigen enters the body. This type of reaction occurs with the participation of T-lymphocytes (hence another name for them - cell-mediated). The attack on the antigen is provided not by antibodies, but by specific clones of T-lymphocytes that have multiplied after previous arrivals of the antigen. Lymphocytes secrete active substances - lymphokines, which can cause inflammatory reactions. Examples of diseases based on type IV reactions are contact dermatitis, bronchial asthma, and rhinitis.

V type – stimulating reactions hypersensitivity. This type of reaction differs from all previous ones in that antibodies interact with cellular receptors intended for hormone molecules. Thus, antibodies “replace” the hormone with its regulatory effect. Depending on the specific receptor, the consequence of contact of antibodies and receptors during type V reactions can be stimulation or inhibition of organ function.

An example of a disease that occurs due to the stimulating effect of antibodies is diffuse toxic goiter. In this case, the antibodies irritate the receptors of the thyroid cells intended for the thyroid-stimulating hormone of the pituitary gland. The consequence is an increase in the production of thyroxine and triiodothyronine by the thyroid gland, the excess of which causes the picture of toxic goiter (Graves' disease).

Another option for type V reactions is the production of antibodies not to the receptors, but to the hormones themselves. In this case, the normal concentration of the hormone in the blood is insufficient, since part of it is neutralized by antibodies. This is how insulin-resistant diabetes occurs (due to insulin inactivation by antibodies), some types of gastritis, anemia, and myasthenia gravis.

Types I–III combine acute allergic reactions of the immediate type, the rest are of the delayed type.

Allergies general and local

In addition to being divided into types (depending on the speed of occurrence of manifestations and pathological mechanisms), allergies are divided into general and local.

With the local version, the signs of an allergic reaction are local (limited) in nature. This type includes the Arthus phenomenon, skin allergic reactions (Overy phenomenon, Praustnitz-Kustner reaction, etc.).

Most immediate reactions are classified as general allergies.

Pseudoallergy

Sometimes conditions arise that are clinically practically indistinguishable from manifestations of allergy, but in fact they are not allergy. In pseudoallergic reactions, there is no main mechanism of allergy - the interaction of antigen with antibody.

A pseudoallergic reaction (the outdated name “idiosyncrasy”) occurs when food, drugs and other substances enter the body, which, without the participation of the immune system, cause the release of histamine and other inflammatory mediators. The consequence of the latter is manifestations very similar to a “standard” allergic reaction.

The cause of such conditions may be a decrease in the neutralizing function of the liver (with hepatitis, cirrhosis, malaria).

The treatment of any diseases of an allergic nature should be carried out by a specialist - an allergist. Attempts at self-medication are ineffective and can lead to the development of severe complications.

• Allergy 325
  • Allergic stomatitis 1
  • Anaphylactic shock 5
  • Urticaria 24
  • Quincke's edema 2
  • Hay fever 13
• Asthma 39
• Dermatitis 245
  • Atopic dermatitis 25
  • Neurodermatitis 20
  • Psoriasis 63
  • Seborrheic dermatitis 15
  • Lyell's syndrome 1
  • Toxidermy 2
  • Eczema 68
• General symptoms 33
  • Runny nose 33

Full or partial reproduction of site materials is possible only if there is an active indexed link to the source. All materials presented on the site are for informational purposes only. Do not self-medicate; recommendations should be given by your attending physician during a face-to-face consultation.

Types of allergic reactions

The human immune system is one of the most complex mechanisms in our body. This system is designed to protect us from various infections and foreign agents. But the excessive load on the immune system, which occurs in conditions of modern ecology and abundance drug therapy, as well as hereditary weakness of the immune system can lead to a malfunction of this delicate mechanism. One of the manifestations of such a malfunction is allergies. The function of the immune system is to produce antibodies, which are protectors. Their main task is to neutralize substances or pathogens (antigens) that have entered the body. But in reality, the immune system sometimes loses control and begins to react to a harmless substance as if it were dangerous. All this triggers allergic reactions (hypersensitivity). Antigens that are the source of allergic reactions are called allergens.

Nowadays, according to statistics, about half of the world's population suffers from various types allergies. To protect yourself from unpleasant manifestations of this disease, it is important to identify in time what kind of allergy is bothering you, prevent repeated contacts with allergens, and also help the body restore correct work its defense mechanism.

Allergic reactions have different manifestations and severity of treatment. In this case, various organs and tissues of our body can be involved in the process. Allergies can manifest themselves as spasms of the bronchi and intestines with the development of suffocation, pain; many are familiar with an allergic runny nose, while others suffer from skin rashes with painful itching. All these manifestations are the result of the release of potent biologically active substances into the blood. active substances- histamine, serotonin, etc. at the time of reaction of the allergen with antibodies. The same substances increase the permeability of blood vessels, especially small ones, contributing to the appearance of an inflammatory reaction, swelling of the internal and external mucous membranes or skin.

Allergic reactions often occur against the background of existing disorders and diseases of other body systems - digestive, nervous, endocrine.

Treating allergies requires a broad approach to the health of the body as a whole, including cleansing it. Folk remedies have their own rich arsenal of means to combat this disease in its various manifestations.

Types of allergic reactions

Allergies can be true or false, manifested by symptoms from various organs and systems.

Sensitization. When it first encounters an allergen, the immune system remembers it. Upon subsequent contacts, she can immediately recognize the agent and quickly and actively attack him. This process is called sensitization. Such an attack may clinically manifest as an allergic reaction to certain allergens. It should be noted that different persons The period of time during which sensitization to an allergen develops can vary from several days to several years.

Atopy. Quite often, patients experience atopy - this is an allergy based on hereditary factors. This is usually expressed in a tendency to produce immunoglobulins E (IgE), which react to environmental allergens (pollen, dust, animal dander, etc.). Clinically, there are 3 main forms of atopy: atopic dermatitis, hay fever (conjunctivitis, allergic rhinitis, pollen bronchial asthma) and atopic asthma with sensitization to household dust, mites and some other household allergens.

Pseudoallergy. This is a false allergy, but which has similar symptoms (asthma, rhinitis, urticaria, swelling). The body of people who do not have atopy is particularly difficult to sensitize. With this allergy there is no genetic predisposition to the production of IgE. Pseudoallergic reactions are not immune in nature.

Respiratory allergy, or allergy respiratory tract. The cause of this type of allergy is small volatile allergens. These can be mold spores, plant pollen, particles of mites, house dust, particles of wool and animal dander, and others. The reaction is expressed in uncontrollable sneezing, runny nose, bronchitis and suffocation. These are allergic conjunctivitis, when the eyes water and are haunted by severe itching of the eyelids, hay fever, which is seasonal and appears regularly, allergic rhinitis, which appears year-round, as well as bronchial asthma.

Skin allergies. Manifests skin allergy in the form of severe itching and burning, rash (swelling, blisters) or eczema (dryness, peeling, change in skin pattern). This allergy can develop as a result of exposure to active toxic substances such as paints, household chemicals, medications and cosmetics, as well as when food products and other similar allergens enter the body through the mucous membrane of the digestive system. They can cause various skin diseases or, as they are also called, allergic dermatoses. This could be eczema, urticaria, atopic dermatitis ( exudative diathesis), contact dermatitis.

Food allergies. There is a true allergic reaction to food and a pseudo-allergy, which is not based on an immune reaction. This may be food intolerance due to enzyme deficiency.

Often pseudo-allergic conditions occur against the background of ingestion of food in which histamine is present or it is released during biochemical transformations in the digestive tract. Often this condition is combined with dysbiosis (disturbance of intestinal microflora). In this situation, you need to seek help from a gastroenterologist, but not from an allergist.

At the heart of the true food allergies lies the immune reaction. Symptoms can be very different (abdominal pain, vomiting, diarrhea, rhinitis, Quincke's edema, urticaria, eczema, itching and even anaphylactic shock) and can occur immediately after direct exposure to the allergen, or with a delay. The most common types of food allergies are allergies to cow's milk, egg whites, chicken, fish, crustaceans (crabs, crayfish, shrimp, etc.), shellfish (oysters, mussels, etc.), as well as certain fruits and vegetables. (garden strawberries, citrus fruits).

Insect allergy, or allergy to insect bites.

Develops from the bite of insects: bees, wasps, hornets, mosquitoes, midges, etc., as well as from inhalation of particles of their bodies or waste products. An allergy to bites usually manifests itself in the form of swelling, as well as an active general reaction (weakness, low blood pressure, hives, suffocation, dizziness). Anaphylactic shock may develop, and general state sharply worsens, weakness occurs, often vomiting, pain and cramps in the abdomen, swelling of the larynx. Then urgent medical attention is needed, otherwise the patient may die. If body particles or waste products of insects (dust mites, moths, cockroaches, etc.) enter the body through inhalation, symptoms of bronchial asthma may occur.

Allergy to medications. True drug allergies in the form of an immune reaction are quite rare. Side effects are more common with overdose, intolerance, pseudo-allergy (when antibodies to the drug are not produced). So, antihistamines promote drowsiness, broad-spectrum antibiotics cause diarrhea against the background of dysbacteriosis.

The most common causes of drug allergies are:

• Penicillin and its derivatives sometimes lead to the development of anaphylactic shock, but more often a rash appears.
• Antitetanus and antidiphtheria serums. Previously, they were prepared on the basis of horse blood, which acted as a strong allergen, but now they use human serum, which is much better and easier to tolerate.
• Insulin, which was made from the pancreas of pigs or whales, which was also a strong allergen. Today natural human insulin is used.
• Non-steroidal anti-inflammatory drugs (analgesics, salicylates), enzyme preparations, radiopaque agents, sulfonamides, B vitamins, local painkillers (anaesthetics, in particular novocaine).

Drug allergies can manifest themselves in different ways, from mild itching to asthma attacks and skin lesions and internal organs difficult character. Anaphylactic shock may also develop.

Infectious allergy

These are increased reactions of the body to non-pathogenic or opportunistic microbes. To a healthy person these bacteria are not dangerous, they do not cause the development of disease. But if you are allergic to one of these microbes, you may develop, for example, infectious-allergic bronchial asthma. Infectious allergies are also closely related to dysbiosis of the mucous membranes.

There is also a group of allergies that are caused by physical factors: allergies to solar radiation (photosensitization), cold, ultraviolet radiation.

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Drawing conclusions

Allergy is a disease that is characterized by disruption of the immune system, which is associated with the recognition of a potential threat to the body. Subsequently, a disruption of the functioning of tissues and organs occurs, characteristic of the inflammatory process. Allergy phenomena are caused by the fact that the body attempts to get rid of those substances that it considers harmful.

This leads to the development of numerous allergy symptoms:

• Swelling of the throat or mouth.
• Difficulty swallowing and/or speaking.
• Rash on any part of the body.
• Redness and itching of the skin.
• Abdominal cramps, nausea and vomiting.
• Sudden feeling of weakness.
• A sharp decrease in blood pressure.
• Weak and fast pulse.
• Dizziness and loss of consciousness.

Even one of these symptoms should give you pause. And if there are two of them, then have no doubt - you have an allergy.

How to treat allergies when there are a large number of medications that cost a lot of money?

Most medications will do no good, and some may even be harmful! At the moment, the only medicine that is officially recommended by the Ministry of Health for the treatment of allergies is.

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Causes of allergies

The main point in the mechanism of allergy development is the body’s sensitization to certain products, drugs and chemicals. A substance to which the human immune system provokes an atypical reaction is called an allergen. The term “allergen” is a collective concept. It includes various groups antigens (substances perceived by the body as foreign) of both natural and anthropogenic origin. Conventionally, allergens are divided into 2 large groups - infectious and non-infectious.

Types of allergens

Infectious	Non-infectious
Pollen deciduous and coniferous trees ( poplar, birch, linden, ash); cereal herbs ( ragweed, fragrant spikelet, meadow bluegrass); plants ( hemp, hops, sage); flowers ( carnation, narcissus, chrysanthemum).	Components of bacteria
Household house and hotel dust; epidermal allergens, that is, dander and animal hair.	Mushroom Components
Allergic reaction type 2 This type of reaction occurs with the participation of immunoglobulins G and M. It is also called cytotoxic because antibodies interact with antigens that are adsorbed on the surface of cells. Therefore, the interaction of antibodies with an antigen occurs with the destruction of cells, which is why the name of the type of reaction follows (“cyto” - cell, “toxis” - destruction). The second type of allergic reaction occurs with thrombocytopenia, hemolytic anemia, and drug allergies. Allergic reaction of the third type An allergic reaction of the third type also occurs with the participation of immunoglobulins G and M. The interaction of antigens and antibodies with the subsequent formation of complexes occurs on the surface of blood vessels. Therefore, this type of reaction is based on damage to the vascular wall. Occurs in systemic lupus erythematosus, rheumatoid arthritis, allergic conjunctivitis. Allergic reaction type 4 The fourth type of allergic reaction is also called a delayed type reaction. It often occurs with damage to the skin, respiratory system and gastrointestinal tract. This type of allergic reaction involves T-lymphocytes and specific antigens. An allergic reaction of the fourth type can be observed with contact dermatitis, tuberculosis, and bronchial asthma. All allergic reactions occur with the release of neurotransmitters. Neurotransmitters are substances that accumulate in the cells of the immune system and lead to the development of the main symptoms. Allergy mediators and their main functions Mediator name Function Histamine It is the main mediator of allergic reactions. Causes a narrowing of the bronchi, thereby causing a cough and a feeling of lack of air. It also increases the permeability of the vascular wall, leading to the release of fluid into the intercellular space. This causes the formation of swelling. The most dangerous effect of histamine is swelling of the larynx. Histamine stimulates intestinal smooth muscle, which leads to the development of diarrhea. Prostaglandins They increase vascular dilatation, causing redness of the skin. A sharp dilation of blood vessels also leads to a drop in blood pressure. Prostaglandins promote increased transudation of fluid from blood vessels into tissues. Leukotrienes They cause spasm of smooth muscles and, accordingly, the organs of which they are composed. The main effect of leukotrienes is a sharp spasm of the bronchi and, as a consequence, the development of cough. Leukotrienes play an important role in the development of bronchial asthma. They also stimulate increased secretion of mucus by epithelial cells, which leads to the appearance of viscous mucus in the lumen of the bronchi. Bradykinins They irritate pain receptors, increasing pain sensations. Dilate blood vessels and increase their permeability. Allergy risk factors In the development of allergies, in addition to the immediate causes, risk factors also play an important role. These are the factors that increase the risk of developing allergies in children and adults. Risk factors for developing allergies are: genetic predisposition; artificial feeding; frequent respiratory tract infections; irrational use of perfumery substances; improper vaccination and incorrect use of serums; the presence of large quantities of household allergens (dust, mites). Genetic predisposition Most of the studies conducted claim that the predisposition to allergies lies in genes. In recent decades, so-called “allergy genes” have even been identified. These genes, or rather their alleles, belong to the HLA histocompatibility complex. The presence of these genes provokes “abnormal” behavior of cells of the immune system and, as a consequence, the development of the allergy itself. Artificial feeding The occurrence of allergies provokes premature transfer of the child to artificial or artificial mixed feeding. The risk of developing atopic dermatitis increases several times if an artificial formula is introduced between 3 and 6 months. This is explained by the fact that the child’s body encounters antigens very early, for which his body is still unprepared. Breast milk contains mother's immunoglobulins, which protect the baby's still unformed immune system. If they do not enter the child’s body or are supplied in insufficient quantities, then the baby’s immunity becomes vulnerable. As a result, the entry of new products (mixture components) into the body provokes an abnormal reaction of the still immature immune system. Frequent respiratory tract infections Frequent respiratory tract infections - rhinitis, bronchitis, tonsillitis, lead to the fact that any allergens are constantly circulating in the body. The constant presence of allergens in the body, even in small quantities, provokes sensitization (hypersensitivity) and causes malfunctions of the immune system. Some bacteria, due to their specific structure, cause autoimmune processes in connective tissue. For example, the components of beta-hemolytic streptococcus, which causes tonsillitis, have a similar structure to the components of heart valves, vascular walls, and kidneys. Therefore, the formation certain immunity to streptococcus is accompanied by the formation of autoallergy and the development of such an autoimmune disease as rheumatism. Irrational use of perfumes Many perfumes and cosmetics used by humans come into close contact with the skin and penetrate the body. Also, cosmetics and perfumes can enter the body through the respiratory tract or conjunctiva of the eyes. However, most of these substances contain strong allergens(the existence of which a person is often unaware). The consequence of this is the development of conjunctivitis, contact dermatitis, and allergic rhinitis. Incorrect vaccination and incorrect use of serums All vaccines must be given according to a certain schedule, that is, according to the calendar. Following these regimens allows you to minimize the development of post-vaccination allergic reactions. Deviation from calendar norms is a risk factor for the development of allergic reactions in response to the administration of serum or vaccine. Presence of large quantities of household allergens (dust, mites) The presence of allergens in a person's daily life is also a risk factor for the development of allergies. Thus, excess dust, which contains strong allergens, can trigger the development of allergic rhinitis or conjunctivitis. Therefore, regular wet cleaning can reduce the risk of developing allergies. A similar situation occurs when contacting occupational allergens. Occupational allergens are substances that a person comes into contact with at work. This could be paint and varnish products, metal vapors and other material. Types of allergies Allergy is a very broad term that combines various pathologies. Therefore, there are many varieties of this disease, which is associated with both a diverse clinical picture and complex mechanism development. Allergies can be classified according to causes, organs and systems that are affected, seasonality and many other criteria. The most common types of allergies are: food allergies; drug allergies; cold allergy; sun allergy; allergies to powder and detergents; home allergies; allergies to cats and dogs. Food allergies A food allergy is a pathological reaction to a certain type of food. This term refers to the appearance various symptoms allergies in response to food consumption. The basis of this reaction is increased sensitivity(sensitization) of the body to certain products. Most often, this type of allergy occurs in children (8 to 10 percent), less often in adults (1 to 2 percent). As you know, products consist of main components - proteins, fats, carbohydrates. The main allergens are glycoproteins - molecules containing both protein and carbohydrate parts. Heat treatment can reduce the allergenicity of these substances. This means that when correct processing Some products may reduce their allergenicity. However, not all allergens change their properties under the influence of temperatures. Thus, the allergens of milk, nuts, eggs, fish and some grains are not destroyed by high temperature, and therefore these products are the most allergenic. Some products may contain several allergens at the same time. For example, milk contains more than 25 different proteins, 5 of which are the strongest allergens. The human body can develop an allergic reaction to one or several proteins at once. In one case or another, he will develop intolerance to milk. Animal meat also contains several allergens - serum albumin and gamma globulin. However, these allergens are quickly destroyed by heat treatment, making meat allergies relatively rare. Much more common is intolerance to certain sausages, which is explained by the addition of various preservatives to them. Chicken eggs have strong allergenic properties. These properties are due to the complex protein composition of this product. Thus, an egg contains more than 20 different proteins, of which 5–6 are the strongest allergens. In this case, egg white is more allergenic than yolk. But, despite this, the human immune system produces antibodies to both the protein and the yolk. Another product to which the body develops a severe allergic reaction is nuts. Even when consuming tiny doses of nuts, the body develops a fatal allergic reaction of the anaphylactic type. Nuts contain heat-stable (not destroyed by exposure to high temperatures) allergens. The strongest of them are the allergens Arah1 and Arah2. They are also present in peanut butter, sweets, and sauces. Therefore, nut allergies are common in both adults and children. The incidence of allergies to certain types of nuts Nut name 25 percent 15 percent Pistachios 11 percent 5 percent All nut allergies are very severe and persist for life. Therefore, this product must be completely excluded from food. Drug allergy A drug allergy is an allergic reaction that develops to a specific drug. Most often, it is regarded as a side effect of the medication and is therefore indicated in the annotation for the drug. Drug allergies are based on specific immunological mechanisms that determine the body’s increased sensitivity (sensitization) to the drug. As a rule, allergies develop after preliminary sensitization. Initially, when the drug enters the body, the human immune system synthesizes antibodies. An antibody is a protein that is produced to neutralize (destroy) antigens that are represented by drug allergens. These antibodies circulate in a free state, and immune system cells (mast cells, macrophages) are adsorbed on their surface. When the drug enters the body for the second time, it specifically binds to previously synthesized antibodies. The formation of an antigen + antibody complex triggers a cascade of reactions that occur with the release of allergy mediators. The release of these substances is accompanied by various pathophysiological reactions that cause allergy symptoms. Histamine leads to redness and swelling of the skin, prostaglandins and leukotrienes cause bronchospasm and cough. The most allergenic medications include: penicillin; bicillin; amidopyrine; Antibiotics were and remain the most allergenic drugs penicillin series. Penicillin causes an allergic reaction such as anaphylactic shock. It is also characterized by the highest incidence of deaths, which are complicated by allergic reactions. Novocaine is in second place in terms of allergenicity. Novocaine is also often accompanied by the development of allergic reactions, but they are less likely to lead to death than with penicillin. Fatalities occur with a frequency of one case per 10,000 allergic reactions. Moreover, most of these cases occur in therapeutic patients. According to recent statistics, the risk of allergic reactions for most drugs is between 1 and 3 percent. The mechanism of development of drug allergies is different. Thus, an allergy may be a consequence of individual intolerance, drug overdose or insufficient kidney function. In the first case, the human immune system produces antibodies either to the drug itself or to its metabolite. A metabolite is the substance into which a drug is converted when it enters the body. Allergenic metabolites are formed by novocaine and some antipsychotic substances. Antibodies are produced directly to the drug for ampicillin, streptomycin, and bicillin. An allergic reaction may also be a consequence of impaired kidney or liver function. These organs are known to play an important role in the metabolism of drugs and their subsequent elimination from the body. Thus, oxidation, hydroxylation and methylation of drugs occur in the liver. As a result, medications turn into inactive metabolites. However, if the liver is damaged and its function is impaired, drug metabolism slows down. The consequence of this is that the medicine circulates longer in the human body and leads to its intoxication. A similar situation occurs if the body’s excretory function is impaired, that is, renal failure is noted. Normally, the kidneys remove all metabolic products from the body, including medications. When this does not happen or does not occur intensively enough, medications and their metabolites linger in the human body, leading to intoxication. There are also medications that themselves promote the release of neurotransmitters of the allergic reaction. For example, polymyxin, trimetaphan and desferal stimulate the release of histamine without involving the immune system. Histamine, being a mediator of allergies, leads to reactions such as redness, swelling, itching. Nerve allergies Nervous allergy is not a completely scientific term. Instead, the terms pseudoallergy or allergy to nervous soil. It is characterized by the appearance of classic allergy symptoms (red spots, swelling, itching) without the penetration of the allergen into the body. It is known that true allergy is a pathological response of the immune system in response to specific allergen. An allergen can be food, dust, pollen, or animal dander. Nerve allergies are mainly characteristic of women, but can also occur in men. It is often preceded by a true allergy, which subsequently creates fear of a possible new allergic episode. For example, a woman had an allergic reaction to some product. Subsequently, she may develop allergy symptoms when consuming other completely non-allergenic products. Fear of the possibility of encountering a new allergen in itself causes the manifestations of allergies. In this case, nerve cells act as allergens and trigger the immune process. Thus, a nervous allergy is nothing more than the body's reaction to stress. During a stressful situation, histamine is produced in the body, which causes allergy symptoms. Moreover, if you conduct specific tests for antigens, the results will be negative, but if you measure the concentration of histamine in the blood, it will be increased. As a rule, nervous allergies are accompanied not only by classic allergy symptoms (redness, swelling), but also by a variety of vegetative signs. Yes, very often skin rashes accompanied by nausea, vomiting, and a feeling of suffocation. People suffering from nervous allergies are characterized by increased irritability, labile emotional background, and sleep problems. Treatment of nerve-related allergies differs from treatment of true allergies. In this case, it involves the prescription of sedatives and anti-anxiety drugs. Allergy to cold Cold allergy or cold allergy is a rare type of allergic reaction that is characterized by the appearance of red spots and blisters when the temperature suddenly drops. Due to the fact that clinical picture This allergic reaction is very similar to urticaria, the pathology is often called cold urticaria. There are two types of cold urticaria - primary (or hereditary) and secondary (acquired). Primary or hereditary cold allergy is a variant of CAPS syndrome. A few minutes after contact with cold air or water, red spots, itching, and burning appear. In severe cases, swelling develops and the skin becomes blistered. Most often, signs of cold urticaria are localized on the face, neck, and arms. Clinical manifestations reach their maximum during the warming period. Regression of symptoms occurs after 30 - 40 minutes. Symptoms can develop not only at the site of contact with the cold irritant, but also around it. This type of allergy is called a reflex allergy. An allergy to cold can develop when a person moves from a warm room to a cold one, or in contact with cold water or when drinking cold drinks. Risk factors for cold allergies are: suffered severe infections; pathology of the thyroid gland; presence of concomitant allergies. Cold allergies can also manifest as allergic rhinitis or conjunctivitis. In the first case, after going out into the cold, a person develops sneezing and nasal congestion. After returning to a warm room, allergy symptoms disappear. Cold allergic conjunctivitis is manifested by lacrimation, pain in the eyes, swelling of the eyelids after a person has been out in the cold air or in contact with cold water. Allergy to the sun Sun allergy is often referred to as photodermatitis. Photodermatitis is the appearance skin signs allergies to the sun. In this case, we are not talking about a true allergy, because there is no allergenic component in the rays of the sun. Most often, photodermatitis develops due to the interaction of ultraviolet rays (rays of the sun) with substances on the skin. These substances can be creams, lotions, or even medications that accumulate in the skin. Most often, exogenous photodermatitis occurs, which develops as a result of the toxic interaction of the sun's rays and substances that settle on the skin. A striking example of such photodermatitis is meadow dermatitis. Thus, most meadow plants during their flowering period release substances called photocoumarins. They settle very quickly on the surface of human skin. When photocoumarins interact with UV rays, red spots, swelling, and sometimes blisters form on the skin. These rashes are accompanied by very severe itching. Not only photocoumarins, but also components of perfumes, lotions, and creams can interact with the rays of the sun. The most toxic components of perfumes that cause severe photodermatitis are para-aminobenzoic acid and eosin. The first component is found in many creams, the second - in lipstick. Some drugs and their metabolites can also be deposited in the skin. Medicines that contribute to the development of photodermatitis include: amiodarone; Trazicor. A separate variant of sun allergy is endogenous photodermatitis. This dermatitis develops due to various metabolic disorders. These disorders are accompanied by the formation and further deposition of intermediate substances in the body. Subsequently, these substances interact with ultraviolet rays to form spots and blisters on the skin. Allergy to powder and detergents Allergies to powder and detergents (household allergies) belong to the category of modern diseases, that is, those whose prevalence has increased significantly in recent decades. This is due to the fact that recently people have begun to use household chemicals much more often, and the quality of powder and other products often does not meet the necessary standards. Causes of household allergies The cause of allergic reactions to household chemicals is the various chemicals that make up these products. An allergen can enter the body through direct use of the product and its contact with the skin. Also, vapors and small particles of powder and detergents can enter the body through inhalation through the respiratory tract. Often allergic reactions are provoked by things that were washed or rinsed with allergenic agents (this is especially common in young children). The most common allergens in household chemicals are: Phosphates. Phosphoric acid salts of inorganic origin. They are added to detergents to reduce water hardness. Present in almost all popular brands of washing powder. In many countries around the world, powders and other products containing phosphates are prohibited. Surfactants (surfactants). The role of these substances is to remove dirt from dishes or fabrics. Surfactants easily penetrate fabric fibers and are not removed from items even after repeated rinsing. It is these substances that in most cases provoke allergies that occur when wearing clothes. The recommended amount of surfactants in any product is no more than 5 percent. Formaldehyde. Used as a preservative to increase the shelf life of household chemicals. In most cases, an allergy provoked by this substance is manifested by complications from the respiratory system (cough, shortness of breath, stuffy nose). Formaldehyde is one of the common causes of allergic asthma. This component is used in the production of fabric bleaches, carpet and glass cleaners, and air fresheners. Chlorine. The purpose of this substance is to remove stubborn stains. An allergic reaction can be triggered by both chlorine itself and its compounds with other substances. A lot of chlorine is found in bleach, as well as in powders and liquids intended for cleaning and disinfection. Dyes and flavors. This group includes various substances intended to improve the color and odor of a detergent or cleaning product. Most dyes and flavors are used in the production of dishwashing detergents. They are also included in conditioners for rinsing things, cleaning and polishing products for furniture, and kitchen equipment. Symptoms Upon contact with an allergen, the first and main symptoms are various skin lesions. Most often, various blisters appear on the hands or parts of the body (in contact with clothing washed with an allergenic agent). These formations are accompanied by itching and burning. Peeling of the skin and swelling are often observed. With prolonged contact with the allergen, extensive blisters and weeping eczema may appear. If the allergen gets on the mucous membrane of the respiratory system, allergic rhinitis develops (coughing, sneezing, dry throat and nose). The intensity of symptoms depends on the age of the person, the amount and aggressiveness of the allergen with which contact occurred. Infants (breastfed children) react especially sharply to household chemicals when using items washed with allergenic laundry detergent. Their allergies manifest themselves not only skin symptoms, but also dysfunction of the digestive system. This may be vomiting, diarrhea, bloating. Home allergies Dust allergy is the most common type of allergy. According to statistics, 40 percent of the world's population suffers from this disease to one degree or another. Dust is a multicomponent substance, which includes a large amount of both organic and inorganic substances. Each of the dust components can act as a provocateur of an allergic reaction. The components of dust are: saprophyte mites; fragments of dead skin of people living in the house; pollen of indoor and outdoor plants; animal hair and skin scales; waste products of various insects; fungal and mold spores; cellulose residues (books, magazines); particles building materials(after renovation). In most cases the reason home allergies mites become saprophytes. They are microscopic insects whose main food source is dead skin particles, as well as other dust components. Their concentration in house dust is quite high. So, in a gram of dust removed from bedding, there are about 1500 mites. Quite often, home allergies are triggered by old books and other paper products. Dust allergies caused by books are also called book or paper allergies. Symptoms of home allergies Dust enters the human body in most cases through the nose or mouth. Therefore, home allergy symptoms most often develop from these organs. The response of the immune system is manifested by itching and burning in the nose and throat, swelling of the mucous membrane, and nasal discharge. Conjunctivitis may also develop, accompanied by itching and swelling of the eyelids, tearing, redness and burning of the eyes. A common symptom of dust is bronchial asthma. Allergic form This disease is one of the most frequently diagnosed. The cause of asthma is most often saprophytes. This symptom manifests itself in the form of an attack, which is characterized by a dry cough, difficult wheezing, shortness of breath, chest pain. Allergy to cats and dogs Allergies to cats and dogs are common types of allergies that affect people regardless of age. The common name for a specific immune system response to pets is fur allergy. In fact, the allergen is not wool, but animal protein foreign to humans, which enters the body through the respiratory or contact route. To date, more than 12 types of proteins have been identified in the body of cats that provoke an inadequate reaction in humans. A smaller number of allergens have been identified in dogs, of which only 2 types are the most active. Causes The protein, which acts as an allergen, can be found not only on wool, but also on other organs, liquids, and waste products of domestic animals. Provocateurs of an allergic reaction are: The level of antigenicity (ability to cause allergies) of the protein depends on the age of the animal, type of coat, and color. Thus, adult dogs and cats provoke allergies much more often than kittens or puppies. There are varieties of pets that are less allergenic than other breeds. Also, according to recent studies, black individuals are more likely than others to provoke an inadequate response of the human immune system. Manifestations This type of allergy is not characterized by seasonal exacerbation, but sometimes it can become more pronounced during the molting period. Since the main route of penetration of the allergen into the body is airborne, the symptoms of this type of allergy most often manifest themselves in the respiratory system. This may include coughing, sneezing, runny nose, or red or watery eyes. The next most common occurrences are skin manifestations allergies due to direct contact with an allergen. This may cause itching, redness, rash, and dry skin. The reaction can manifest itself both directly in the contact area and throughout the body. Animals that do not cause allergies Today, there are no breeds of dogs or cats that do not initiate allergic reactions in people with hypertrophied sensitivity to animal protein. Numerous advertisements about hypoallergenic animals are nothing more than a ploy on the part of breeders. But there are breeds that, due to certain characteristics, provoke allergies to a lesser extent. Those who are planning to buy a pet, but one of the family members is allergic to animals, should focus on these criteria. Characteristics of less allergenic dogs and cats are: complete absence of fur; breeds with wool that does not have an undercoat; animals with rough fur; individuals of small or dwarf size; breeds whose proteins are less allergenic. Among cats, breeds such as the Sphynx, Oriental Shorthair, Baltic and Javan cats have one or more of these characteristics. An interesting fact is that Siberian cats, which are distinguished by thick and long hair with an undercoat, also belong to the category of less allergenic animals. Among dogs, allergies are less likely to be caused by Yorkies, Bichon Frize, Maltese, Mexican and Chinese breeds. Seasonal allergies Seasonal allergies are the development of an allergic reaction at certain times of the year. Most often, allergists encounter allergies in the spring and autumn period time of year. As a rule, it manifests itself in the form of rhinitis, conjunctivitis or bronchial asthma. The cause of these pathologies is pollen from various grasses, trees, and shrubs. Allergy to pollen, to flowers Pollen allergies fall into the category of common seasonal diseases. About 6 percent of the total population of the planet suffers from hypersensitivity to pollen. People aged 20 to 40 years are most susceptible to hay fever. Causes There are about 50 representatives of the flora, the pollen of which can be the initiator of allergic reactions. Being small in size, pollen is carried by wind and insects and, together with the air, penetrates the human respiratory tract. Significant factor in the distribution of pollen is Poplar fluff, which, due to its structure, adsorbs and transfers pollen not only from poplar, but also from other plants. Trees and weeds can act as a source of allergenic pollen. Each specific region is characterized by the predominance of certain plants pollinated by pollen. Summer (all 3 months). Typical for summer acute manifestation hay fever in those who are susceptible to pollen from cereals and meadow grasses. In June, the concentration of poplar fluff increases, which provokes allergies in those who are sensitive to it. A reaction to poplar fluff (unless it is caused by the pollen the fluff carries) is less severe than a pollen allergy. Autumn (September, October). In autumn, the air is dominated by weed pollen and medicinal plants, which causes a deterioration in the condition of those who suffer from hypersensitivity to the pollen of these crops. Symptoms The most characteristic symptom of hay fever is rhinoconjunctival syndrome, which is manifested by deterioration of the eyes, nose and upper respiratory tract. The very first to appear is itching and burning of the eyes, a sensation in the eye foreign body. After some time, sensitivity to light increases, tears, redness and swelling of the eyelids appear. Soon itching in the nose and pain in the sinuses appear. A distinctive feature of hay fever is the symptom of frequent bouts of sneezing. In some cases, sneezing is accompanied by mucus discharge from the nose. Also, with pollen allergies, patients are often bothered by pain in the parotid area, crackling and discomfort in the ears while chewing food. Peculiarities According to recent studies, this disease is often paired with latex allergy. Therefore, during an exacerbation, patients with hay fever are advised to refrain from using rubber products (gloves, condoms, baby pacifiers). In most cases, patients with hay fever develop a reaction only to certain types of plants or trees. Therefore, the exacerbation of the disease occurs at one time or another during the year. Often, when an allergy occurs to one type of plant, hypersensitivity to other crops of that family subsequently develops. Often with hay fever, cross reactions with other plant products. Cross reactions can be as follows: weeds – vegetable oil and sunflower seeds, herbal drinks, spices (coriander, cinnamon); meadow grasses – yeast-based drinks (kvass, beer), cereals, flour products; trees - birch sap, fruits of garden trees with seeds; medicinal herbs (in particular, dandelion) - bananas, melon, watermelon; cereal crops– cereals, sorrel. Before use, you should consult a specialist.

An allergic reaction is a pathological response of the body's defense system to the influence of an irritant - an allergen. Ultimately, the body begins to synthesize antibodies that are designed to resist allergens, but are perceived by it as hostile.

Thus, antibodies lead not only to the neutralization of the allergen, but also to damage to healthy tissues and provoke Various types allergic reactions. Most often, allergies occur in one form or another of skin dermatosis.

Types of allergic reactions: etiological and provoking factors

Etiological factors causing development different types of allergic reactions are currently not well studied. They are triggered by previously occurring sensitization of the body by an allergen (one or more). An allergen is a substance to which the defense system responds with an atypical reaction. Allergens can be any antigens that the body regards as foreign.

All allergens are conventionally divided into 2 groups:

1. Infectious:
. bacterial particles;
. mushroom components;
. components of viruses;
. helminth particles.

2. Non-infectious:
. plant pollen;
. dust (street, book, home);
. detergents and cosmetics (powders, soaps, perfumes, oils, gels, shampoos);
. food products (milk, seafood, chocolate, fish, citrus fruits, honey, nuts);
. fur, skin particles, saliva of animals (mainly cats and dogs);
. chemicals (varnishes, paints, resins, solvents);
. poisons of animal origin (bites of bees, bumblebees, wasps);
. medications (mainly antibiotics);
. latex (disposable gloves, condoms);
. ultra-violet rays;
. cold;
. synthetic clothing.

Factors that provoke various types of allergic reactions

To trigger the manifestations of an allergic reaction, in addition to exposure to the allergen, there must be one or more provoking factors that significantly increase the risk of allergies.

The occurrence of an allergic reaction has a direct connection with the individual susceptibility of the body. The effect of one allergen on the body different people varies.

So, for example, one person consumes seafood without consequences, while in another it leads to the development of some type of allergic reaction.

Types of allergic reactions: classification

There are 4 types of allergic reactions:
. First type
This is an immediate reaction that occurs as an anaphylactic one (Quincke's edema, anaphylactic shock, bronchial asthma, allergic rhinitis or urticaria). After exposure to an allergen, the body’s response in the form of an allergy is formed after a few minutes to several hours.

. Second type
It occurs as a cytotoxic reaction; it is based on cytolysis (destruction) of cells. It develops more slowly and lasts longer (up to several hours). Manifested by thrombocytopenia, hemolytic anemia, toxic allergies.

. Third type
It is called the Arthus phenomenon and occurs as an immunocomplex reaction. It is based on the formation of complexes of antibodies and allergens (antigens), which are deposited on the walls of the capillaries and destroy them. This reaction continues for several days. Manifests allergic conjunctivitis, glomerulonephritis, systemic lupus erythematosus, hemorrhagic vasculitis.

. Fourth type
It occurs as a delayed type of allergic reaction or late hypersensitization. Develops over at least 24 hours. Manifests itself as contact dermatitis, rhinitis, asthma.

Types of allergic reactions: skin manifestations

The main manifestations of skin allergic reactions include:

. atopic dermatitis- manifested by dryness, itching and irritation of the skin;

. contact dermatitis- accompanied by hyperemia, swelling, itching of the skin area in contact with the allergen, the appearance of rashes in the form of papules and vesicles;

. hives- similar to a nettle burn and is accompanied by the appearance of hyperemic spots raised above the surface of the skin that tend to merge, intense itching, weakness, dizziness;

. eczema- manifests itself as a multiple rash in the form of vesicles with serous contents, which tend to open and form erosions, and subsequently scabs and scars;

. toxicoderma- accompanied by a profuse pink or red rash, which later leads to the formation of blisters;

. neurodermatitis- manifested by night itching, rashes in the form of hyperemic spots, which later merge into plaques, swelling of the skin;

. Quincke's edema- accompanied by swelling of the mucous membranes, swelling of subcutaneous fatty tissue (more often manifested on the face), hoarseness, difficulty breathing, cough;

. Lyell's syndrome- refers to severe drug allergies, manifested by the appearance of vesicles, which, when opened, form cracks, erosions, ulcers on the skin;

. Steven-Johnson syndrome- proceeds according to type exudative erythema with the appearance of a bright red bleeding rash, the appearance of itching, swelling, fever, weakness, myalgia, headaches.
Methods for identifying types of allergic reactions

In order to confirm the diagnosis and identify a specific irritant, various tests and analyzes are performed

. Blood tests
With the development of allergies, an increased level of eosinophils and class E immunoglobulins is detected in the peripheral blood.

. Skin tests
The patient is injected intradermally with various allergens, their number can be up to 20 varieties. Each allergen is applied to a specific skin area. Positive reaction manifests itself within half an hour in the form of redness, itching and swelling. How more intense manifestations, those stronger effect allergen for a given patient.

You should stop taking antihistamines 48 hours before skin testing because they may cause false test results.

. Skin tests
Applications of paraffin, petroleum jelly and a number of allergens (chrome, benzocaine, medications) are applied to the skin. Applications must be kept on the skin for 24 hours. Used in the diagnosis of contact dermatitis and eczema.
. Provocative tests
It is 100% reliable in determining the cause of allergies, but the most dangerous method examinations. Provocative tests are performed in a hospital under the supervision of a group of doctors. The suspected allergen is injected into digestive tract, nasopharynx, sublingual.

ALLERGY

The term allergy comes from two Greek words allos - different, ergon - acting. And a different, altered effect of certain substances on the body is literally translated. The term “allergy” was proposed by Pirquet in 1906. Allergy is considered as a form of immune pathology, since allergy and immunity are provided by the same apparatus - the lymphoid system.

Immunological and allergic reactions are aimed at maintaining antigenic homeostasis and eliminating the foreign agent. However, there are some differences between the reaction to the re-entry of an allergen into the body and the immune response to an antigen. Thus, allergies can be caused by factors (cold, ultraviolet rays, ionizing radiation), the effect of which on the body is not accompanied by immune reactions. Allergic reactions occur in stages with the inevitable destruction of blood, vessel walls, and tissue elements, which in principle distinguishes allergies from immunological reactivity. Allergies develop with the predominant participation of class E immunoglobulins, which are rarely involved in the mechanism of immunity formation. With the help of allergic reactions in the form of anaphylactic shock, inflammation, swelling, etc., the body is faster freed from the antigen (allergen) than with an immune response.

Allergy– this is an increased and perverted reactivity of the body to the action of substances of antigenic and non-antigenic origin.

Substances to which the body’s reaction can be distorted or which can distort the body’s response are called allergens. Allergens have all the properties of antigens (macromolecularity, predominantly protein nature, foreignness to a given organism, etc.). However, allergic reactions can be caused by substances not only of an antigenic nature, but also by substances that do not have these properties. These include many micromolecular compounds, such as drugs, simple chemicals (bromine, iodine, chromium, nickel), as well as more complex non-protein products (some microbial products, polysaccharides, etc.). These substances are called haptens.

Allergens can be a variety of substances. The number of allergens that can cause allergic reactions is enormous. They are divided into allergens exogenous, i.e. entering the body from the external environment, and endogenous, arising in the body under the influence of damaging factors or when one’s own tissues combine with non-antigenic foreign substances.

Exogenous allergens include:

Infectious – a variety of pathogens of infectious diseases and their metabolic products (bacterial, viral, fungal, coccal forms) - which, once entering the body, increase the sensitivity of the body and upon repeated entry, the phenomenon of allergy occurs;

not infectious(food, household, animal, chemical, medicinal and plant origin).

household (organic and inorganic substances - house dust, library dust, etc.). Household allergens are complex allergens, which include dust particles (clothing, bedding, furniture), mushrooms (in damp rooms), particles of domestic insects, bacteria (non-pathogenic staphylococci, etc.). The main allergenic component of house dust is mites (live, dead, their shed skins and excrement);

plant substances (for example: pollen of plants such as white bentgrass, meadow timothy, meadow bluegrass, hedgehog grass, meadow fescue, etc.);

substances of animal origin, for example, exfoliating epidermis, wool, fluff, dandruff, particles of sweat;

blood serum;

some nutrients (strawberries, strawberries, protein chicken egg(albumin), milk, honey, etc.). Many foods can be allergens. However, most often they are fish, wheat, beans, and tomatoes. Allergens can also be added to food products chemicals (antioxidants, dyes, aromatics and other substances).

medicinal substances (serums, vaccines, antibiotics, some chemotherapy drugs). Any drug (except some components biological fluids - sodium chloride, glucose, etc.) can lead to the development of drug allergies. Drugs or their metabolites are usually haptens;

some physical and chemical factors (synthetic detergents, pesticides, herbicides, etc.).

To allergens endogenous origin include autoallergens.

Autoallergens- call the tissues, cells, or proteins of the body that are formed into given organism autoantibodies or sensitized lymphocytes and the development of an autoallergic process.

Autoallergens can be formed from the body’s own proteins as a result of exposure to cold, high temperature, ionizing radiation, or when microbes are attached to them.

All autoallergens can be divided into 2 groups: natural (primary) and acquired (secondary).

Natural autoallergens are allergens that are already contained in the body, these include some proteins of normal tissues (main protein), tissue of the lens of the eye, testes, thyroid gland, Gray matter brain Under normal conditions, these proteins are well isolated from immunologically competent cells and therefore they do not cause an autoallergic process. However, if these tissues are damaged, for example, due to injury, inflammation, the insulation is disrupted, immunologically competent cells come into contact with these proteins and an autoallergic process may develop.

Purchased autoallergens - based on their origin, they can be divided into two subgroups: non-infectious and infectious. The subgroup of non-infectious autoallergens includes protein denaturation products. It has been established that blood and tissue proteins under various pathological conditions acquire properties foreign to the body and become autoallergens. They are found in burns and radiation sickness, and in dystrophy. In all these cases, changes occur to the proteins that make them foreign to the body. Thus, the antigenic properties of whey proteins can be changed by adding iodine to their molecule. nitro or diazo groups, and antibodies can be formed against such altered proteins.

The subgroup of infectious autoallergens includes substances formed as a result of the combination of microbial toxins and other products of infectious origin that have entered the body with tissue cells and proteins. Such complex autoallergens can, for example, be formed by combining some components of streptococcus with proteins of myocardial connective tissue. This subgroup also includes intermediate autoallergens. They are formed during the interaction of viruses with tissue cells and differ from both the virus and the tissue.

Predisposing factors in the occurrence of allergies are:

frequent vaccinations

uncontrolled use of drugs

taking improperly stored medications

contributing factor Allergies are caused by frequent contact with chemicals.

Allergens enter the body in various ways: enterally, parenterally, through the respiratory tract, after application to the skin, mucous membranes (easier through damaged ones), transplacentally, through general and local exposure to physical factors.

Mechanism of allergy development

There are cellular and humoral mechanisms allergic reactions. They are interconnected and considered in an inextricable unity. Allergic antibodies are formed in some cells, which are then released from them and accumulate in the blood and other body fluids (humoral factors). Antibodies act through source cells chemical substances that have a toxic effect. These are mediators, or intermediaries, of allergic damage to organs and tissues. So, some cells create the basis for allergies, producing specific antibodies - reagins; others are the active link, they are called allergy effector cells.

Within the T-lymphocyte system, there are T-lymphocytes that help certain clones of B-lymphocytes produce specific antibodies to allergens. These are T-cells - helpers. In addition to them, there are also cells that provide delayed-type allergic reactions: effector T-lymphocytes, as well as suppressor T-lymphocytes that suppress allergic reactions. Allergic antibodies, including reagins, are formed by the descendants of B lymphocytes - plasma cells. B lymphocytes are involved in the formation of antibodies only with appropriate support from T lymphocytes - helpers. In the process of antibody formation, another cell is involved - a macrophage. The main function of macrophages is to maintain constant internal environment body, its homeostasis. For absorption and digestion foreign substances in the macrophage there is a special apparatus consisting of vacuoles, vesicles filled with highly active enzymes that break down proteins, fats, carbohydrates and nucleic acids.

Protein allergens entering the body are filtered through macrophages. More or less complete breakdown of allergens occurs in the lysosomes of macrophages. When they completely disintegrate, the antigen loses its ability to cause the formation of antibodies and immunological tolerance develops to it. The partially cleaved allergen from the lysosomes again “floats” to the surface of the outer membrane of the macrophage. There is evidence that it “grabs” messenger ribonucleic acid (and RNA) from the cell and thereby acquires even greater immunogenicity. Such a modified allergen comes into contact with the membrane receptors of a certain clone of lymphocytes and causes the formation of specific antibodies in them. The first portions of formed antibodies, in turn, automatically enhance the production of subsequent portions of antibodies. Normally, after passing the stage during which the amount of antibodies sufficient to protect the body has time to accumulate, the synthesis of antibodies automatically stops. Negative feedback is triggered, protecting against excess antibodies and related undesirable consequences– from tissue sensitization to the allergen. In organisms with an allergic constitution, this regulatory mechanism does not work clearly. An excess of antibodies accumulates in the body, which subsequently cause sensitization and tissue damage.

Immediate allergies are caused by sensitizing antibodies. Sensitizing antibodies are called reagins. They differ from other classes of antibodies in their chemical structure. Immunoglobulin E (reagins) is contained in the blood in negligibly small quantities and is destroyed quite quickly and is completely eliminated from the blood after 5-6 days. They most readily attach to skin cells, smooth muscles, mucosal epithelium, mast cells, leukocytes, blood platelets, nerve cells. Reagins are bivalent. At one end they connect with the cells of the skin or internal organs, at the other - with the determinant group medicinal product or other allergen.

The cells that form allergic antibodies are not distributed diffusely throughout the immune organs, but are most concentrated in the tonsils, bronchial and retroperitoneal lymph nodes.

The following stages can be distinguished in the development of allergies:

stage of immune reactions

stage of pathochemical disorders

stage of pathophysiological disorders

Stage of immune reactions: This stage is characterized by the accumulation in the body of antibodies specific to a given allergen. The allergen, entering the body, is fixed in the cells of the reticuloendothelial system and causes plasmatization of lymphoid cells, in which the formation of antibodies begins. Allergic antibodies have a high degree of specificity, i.e. connect only with the allergen that caused their formation. Sensitizing antibodies are called reagins. Reagins are bivalent; at one end they connect to the cells of the skin or internal organs, and at the other they attach the determinant group of a drug or other allergen. Antibodies of class E and immune lymphocytes almost do not circulate in the blood, but go into the tissues and become fixed on cells, increasing sensitivity, i.e. sensitize (sensibilis - sensitive) body tissues to repeated introduction (ingress) of the allergen. This ends the first stage of allergy occurrence - the stage of immune reactions.

Stage 2 – pathochemical disorders. When an allergen enters the body again, antibodies of class. E (reagins) react with the allergen on the surface of a wide variety of cells, even nerve cells, and damage them. Fixed in the tissues, this complex causes a number of metabolic changes, and first of all, the amount of oxygen absorbed by the tissues changes (initially increases and then decreases). Under the influence of the allergen-antibody complex, tissue and cellular proteolytic and lipolytic enzymes are activated, which leads to dysfunction of the corresponding cells. As a result, a number of biologically active substances are released from the cells: histamine, serotonin, bradykinin, slow reacting substance of anaphylaxis (MRS-A).

In the human and animal body, histamine is found in mast cells of connective tissue, blood basophils, and, to a lesser extent, in neutrophilic leukocytes, platelets, smooth and striated muscles, liver cells, and gastrointestinal epithelium. The participation of histamine is expressed in the fact that it causes spasm of smooth muscles and increases the permeability of blood capillaries, causing edema, urticaria, petechiae, and has an exciting effect on the nerve centers, which is then replaced by depression. It irritates the nerve endings of the skin and causes itching. Histamine increases the hydrophilicity of the fibers of loose connective tissue, promoting the binding of water in the tissues and the occurrence of extensive Quincke's edema.

Serotonin is found in almost all tissues of the body, but it is especially abundant in mast cells of connective tissue, spleen cells, platelets, pancreas, and some nerve cells. It has less effect on the smooth muscles of the bronchi and bronchioles, but it causes severe spasm of arterioles (small arteries) and impaired blood circulation.

Bradykinin causes a sharp spasm of the smooth muscles of the intestines and uterus, to a lesser extent the bronchi, dilates blood capillaries, increases their permeability, reduces the tone of arterioles and causes hypotension.

“MRS – A” - it easily binds to the lipids of the cell membrane and disrupts its permeability to ions. First of all, the flow of calcium ions into the cell is affected, and it loses the ability to relax. Therefore, when MPC-A accumulates, spasms occur. If, under the influence of histamine, bronchospasm develops within a few seconds or minutes, then under the influence of MRS, the same bronchiole spasm develops gradually, but lasts for hours.

This ends the second stage of pathochemical disorders.

Stage 3 - pathophysiological disorders. The pathophysiological stage of allergic reactions is the final expression of those immune and pathochemical processes that took place after the introduction of a specific allergen into the sensitized organism. It consists of the reaction of cells, tissues, organs and the body as a whole damaged by the allergen.

Allergic damage to individual cells has been well studied using the example of red blood cells, platelets, blood leukocytes, connective tissue cells - histiocytes, mast cells, etc. The damage also extends to nerve and smooth muscle cells, heart muscle, etc.

The response of each damaged cell is determined by its physiological characteristics.

Thus, an electrical damage potential arises in a nerve cell, and in smooth muscle myofibrils, red blood cells undergo hemolysis. Damage to leukocytes is expressed in the redistribution of glycogen in the protoplasm, in lysis. Granular cells swell and throw out their granules - cell degranulation occurs. The latter process is especially pronounced in blood basophils and mast cells of loose connective tissue, the granules of which are especially rich in various biologically active substances that are mediators of allergic reactions.

Allergic damage to tissues and organs occurs as a result of damage to the cells that make up this tissue, on the one hand, and as a result of disruption of the nervous and humoral regulation of the functions of these organs, on the other. Thus, contracture of the smooth muscles of the small bronchi results in bronchospasm and a decrease in the lumen of the airways.

Dilatation of blood vessels and increased capillary permeability, leading to the exudation of the liquid part of the blood into the tissue and causing the occurrence of urticaria, Quincke's edema, depends both on the effect of allergy mediators (histamine, serotonin) on the vessels and on the disorder of peripheral and central regulation of vascular tone. The general expression of the pathophysiological phase of allergic reactions is the reaction of the body as a whole, certain allergic diseases or allergic syndromes.